Reflector lamp



.Ma 1s,194s. 4 KURLANDER 2,441,824

REFLECTOR LAMP Filed Oct. 16,. 1943 INVENTOR (13H. KU/EZ/WVDFE.

ATTORNEY Patented May 18, 1948 REFLECTOR LAMP Jolm H. Kin-lander, Nutley, N. J., assignor .to Westinghouse Electric Corporation, East Pittsburgh, la., a corporation of Pennsylvania Application October 16, 1943, Serial No. 506,479

12 Claims. (CL 176-34) This invention relates to optical systems, and more particularly to a reflector lamp of the type described and claimed in my application Serial No. 474,372, filed February 1943, and Ow d by the assignee of the present application.

The principal object of my invention, generally considered, is to produce a lamp particularly adapted for illuminating a, reticle used in optical systems such as those for gun sights, where special conditions arise, such as the directing of the light in a special way, on a reticle of abnormal size, or where particular care must be taken to avoid breakage of the filament.

Other objects and advantages of the invention are similar to those enumerated in my co-pending application above-identified, and still others will become apparent as the description proceeds.

Referring to the drawing which except for Fig. 7 is approximately to scale, but enlarged:

Fig. l is a side elevational view, with a portion of a bulb broken away, of a lamp embodying my invention.

Fig. 2 is a perspective view of the mount of the lamp of Fig. l.

Fig. 3 is a view corresponding generally to Fig. 1, but showing a modification.

Fig. 4 is a perspective view of the mount of the lamp of Fig. 3.

Fig. 5 is a view corresponding generally to Fig. 3, but showing another modification.

Fig. 6 is a perspective view of the mount of the lamp of Fig. 5.

Fig. 7 is a wiring diagram for the filaments of the lamp of Figs. 5 and 6.

Fig. 8 is a view corresponding generally to Fig. 5, but showing a further embodiment of my invention.

Fig. 9 is a view corresponding generally to Fig. 8, but showing, as a still further embodiment of my invention, a lamp with only one filament.

Referring to the drawings in detail, like parts being designated by like reference characters, and first considering the embodiment illustrated in Figs. 1 and 2, there is shown an incandescent electric lamp l I having a generally spherical bulb l2, of the type designated by the Westinghouse Electric 82 Manufacturing Company as G-9, which has an outside diameter of about 1%". A bulb of such a size is illustrated because it fits present equipment. However, I do not wish to be so limited as the .bulb may be of any suitable size.

Said bulb l2 has a generally cylindrical neck portion 13 projecting therefrom and-closed by a flare l4, with an exhaust aperture 21. The flare, in the present embodiment, has three leads con necting respectively with the filament supports l5, l6 and [1, extending from the press iii. The filament supports I5 and I6 hold the major or primary filament IS in a normally horizontal position between their free ends, considering the normal position of the lamp as base down, while the support I! and an extension 21 welded to the support l5, as at 22, holds the minor filament 23 also in a normally horizontal position, but in a vertical plane disposed at right angles to the vertical plane of the major filament.

Inasmuch as the present lamp is the type in which the light is to be taken out along the axis of the bulb, the vertical planes of the filaments l9 and 23 intersect on said axis, and the supports extend generally parallel thereto, flaring slightly, however, from the press 18.

A reflecting coating 24 is provided on the exterior or interior of the bulb and desirably covers appreciably more than one-half of the area thereof, as shown most clearly in Fig. 1, in order to facilitate manufacture. The bulb may be initially completely coated with the reflecting material, a mask applied thereover, as indicated at 25, and the portion outside of said mask removed as by sand blasting or other suitable means. The coating may be of aluminum, silver, gold or other specular material. If a colored material, such as gold, is used, selective reflection will occur, possibly making it unnecessary to have a color filter to use therewith to make the reticle image contrast with the background.

As in my co-pending application, Serial No. 474,372, previously referred to, I make use of the image-forming properties of the smooth spherical concave reflector surface on the bulb, and place the major filament l9 at a distance from the center of the bulb equal to one-half of the radiusof the curvature, so that the portion of the bulb approximating a parabolic surface projects substantially parallel light rays out of the top or axial portion thereof. In other words, the filament is placed at what corresponds with the focal point of an approximate paraboloid of revolution, so that the image is reflected approximately to infinity, as with a searchlight reflector.

The minor filament 23 is desirably disposed so that when viewed from above it makes a cross with the major filament, as illustrated. It is desirably disposed close, say at a distance of about two or three millimeters, but at a safe distance from the major filament. If desired, it may be made of the same size. Voltage may be 28 and the candlepower 2| for each filament. In

instance, both filaments are preferably of the coiled-coil type. However. if desired, the

- minor filament may be straight or coiled, and the of illumination therefrom, the part that is not coated with the reflecting surface may be frosted as indicated at 28.

Referring now to the embodiment of my in-' vention illustrated in Figs. 3 and 4, there is shown a bulb I 2", which may be identical with that of Fig. 1, enclosing a mount which is designed to project light at an angle of 50 to the horizontal, rather than vertically. Therefore, the center of the major filament i9 is rotated through 40 two of them direct the light from the lamp in a mal position like the lamp of Figs. 1 to 5, incluhorizontal direction, assuming a base-down norsive, of my co-pending application Serial No.

, 474,372, previously referred to. However, as in the same reason, and the frosting 26*, if emfrom the vertical and held by filament supports 4 i5 and iii extending from the press l8. In

the same way the minor filament 23' is rotated through an angle of about 40 and held in position by connection with the support i8 and another support I 1 it. being understood that all of the supports are bent as illustrated in 'Figs.- 3 and 4, and provided with suitable lead-in conductors extending out of the bulb through the flare H, with exhaust aperture 21. v

The reflecting coating 24' may be applied as in the. preceding embodiment, except that it terminates at an edge 28 lying in a plane disposed at an angle of 40 to the horizontal, so that the axis of the light projected from the bulb is normal to said plane. Except as specifically described in connection-with the present embodiment, the same may correspond with that of the preceding embodiment.

The standard electric potential used on aircraft today is 28 volts. It. is generally necessary, with the small bulbs used in aircraft, to concentrate the filament as much as possible due to space limitations. Coiled-coil tungsten filaments are usual under such conditions. Unfortunately such coiled-coil filaments lack strength under shock and vibration so that they fail early in life. Such early failures are disastrous in lamps employed for illuminating optical sights.

In order to make use of the strong single or simple coil filaments in such lamps, and still provide an emergency or "stand-by filament, I have provided a lamp li as illustrated in Figs. 5 and 6. This lamp is for directing light horizontally, like the lamp H of my co-pending application Serial No. 474,372, previously referred to, and has a bulb l2", such as those of the preceding embodiments, but the flare it holds four, instead of three, filament supports designated by the reference characters I6, I8 ii and 29. The supports it and li are for the filament i9", corthe preceding embodiments in the present application. the reflecting coating 24 desirably terminated at an edge 28 lying in avertical plane, covers more than one half of the bulb area for ployed, covers the remainder. Referring now to Fig. 7, there is shown a switc 32 so positioned with respect to the leads 33, 34, 35 and 36, as illustrated, that when said switch is in the first position, or that to the left shown in full lines, the'filaments ifl and 23 are energized in seriesfrom the 28 volt power source; when it is in the middle position illustrated in dotted lines, the filaments 23 and iii are energized; and when it is in the right hand position, the filaments 19 and 3| are energized.

Referring now to the embodiment of my invention: illustrated in Fig. 8, there is shown an incandescent electric lamp il, having a bulb i2 rotund as. in the preceding embodiments, but generally ellipsoidal in shape about an axis perpendicular to that of its base 31, that is, elongated laterally from its axis into ellipsoidal form. Said bulb i2 has a generally cylindrical neck portion l3 projecting from a side thereof, or coaxial with the minor axis of the ellipsoidal bulb responding in position with the major filament volt, 15 candlepowerand so connected that any two can be switched on in series to operate as a major single 28 volt filament, thereby achieving the required strength and still olfiering a, standby. or emergency filament, should-one of the three filament coils break or burn out. Failure of two coils would have to occur before the lamp becomes inoperative. It will be understoo howsection. It will be'understood that the main portion of the bulb is the same in plan as in side elevation, that is, said portion is an ellipsoid of revolution about a normally horizontal, rather than a normally vertical, axis.

The neck portion |3 is, as in the previous embodiments, desirably closed by a flare I 4 which in the present embodiment has three leads i5. i6 and I1", the last of which is directly behind the lead I 6 (like the lead I1 is directly behind the lead l6" as viewed in Fig. 3), all of said leads extending from the press l8. The filament supports H and |8 hold the major or primary filament i9 in a normally vertical position between their free ends, considering the normal position of the lamp as base down, and with the center of the filament disposed at one of the facial the ellipsoid of revolution, while the supports I 6 and ii hold the minor filament 239 in a position, say two or three mm. toward the center of the bulb from the filament i9, so as to be at a safe distance therefrom while still approximately at the desired focal point. The filament 23 extends horizontally with its axis lying in a vertical plane which is perpendicular to the axis of the ellipsoid and parallel to the corresponding plane of the axis of the filament l9.

Inasmuch as the present lamp is of the type in which the light is to be taken out along the axis of the ellipsoid, that is, horizontally, the axial plane of the filament 23 intersects the filament reasons previously pointed out in connection with the first embodiment.

The lamp of the present embodiment is particularly adapted for illuminating reticles which are quite large in order to achieve greater sighting accuracy. As will be seen from the lines of reflection, the light passing out of the uncoated. or frosted, portion 28 of the bulb I2", diverges rather than comes out in parallel rays and, therefore, is adapted to efilciently illuminate a relatively large reticle.

Fig. 9 shows a lamp which is alternative to that of Figs. 1 and 2 in that the light is taken .out of and/or projected axially from the bulb l2 which in this instance is an ellipsoid of revolution about the vertical axis or that of the base Otherwise the construction is identical with that of Figs. 1 and 2 except that a single filament l 9* is employed and positioned at the upper focus of the ellipsoid or that remote from the neck,

rather than halfway between the center of the sphere and the reflecting coating. The lines of reflection from the filament are shown in order to indicate how the light is reflected from the coating 24 and passes out of the uncoated, or frosted, upper end portion 26 Although preferred embodiments of my invention have been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims. It will also be understood that in each form of bulb and filament position, I may use a single or more than one filament, a plurality of filaments, however, being preferred in order to have a spare or "stand-by in case one burns out at a critical time.

Iclaim:

1. A reflector lamp comprising a generally spherical bulb with a neck portion extending therefrom, a mount disposed in said neck portion and comprising a helical filament and its lead-in conductors, the axis of said filament being straight for its entire length, and a reflecting coating on more than one-half 01' said bulb, said filament being offset from the center of said bulb and with its axis intersecting a line through the bulb center and perpendicular to the plane of the edge of the reflecting coating.

2. A reflector lamp comprising a generally spherical bulb with a neck portion extending therefrom, a helical mount disposed in said neck portion and comprising a filament and its leadin conductors, the axis of said filament being straight for its entire length, and a reflecting coating on more than one-half of said spherical portion, said filament being disposed approximately midway between the central portion of said reflector coating and the center of said bulb and with its axis intersecting a line through the bulb center and perpendicular to the plane of the edge of the reflector coating, so that the coating reflects the light from said filament in approximately parallel rays;

3. A reflector lamp comprising. a bulb formed as a simple ellipsoid of revolution with a neck portion extending therefrom, and with its axis as a minor axis of an elliptical axial section, a mount disposed in said neck portion and comprising a filament and its lead-in conductors, and a reflecting coating on more than one-half of said ellipsoid, said filament being disposed at one of the foci of said bulb.

4. A reflector lamp comprising a bulb with a neck portion extending therefrom, a mount disposed in said neck portion and comprising a major filament and its two lead-in conductors, a minor filament connected to one of said conductors and-a third conductor and closely disposed with respect to said major filament, and a reflector coating on more than one-half of said bulb, said major filament being offset from the center of said bulb toward the center of said coating, and'the minor filament being disposed between said major filament and the center of saidbulb.

5. A reflector lamp comprising a bulb formed as a simple ellipsoid of revolution with a neck portion extending therefrom and with its axis as a minor axis of an elliptical axial section, a mount disposed in said neck portion and com prising a helical filament and its lead-in conductor, the axis of said filament being straight for its entire length. and a reflecting coating on more than one half of said bulb and terminating in an edge defining a plane, said filament being disposed at one of the foci of said bulb, with its axisintersectin a line through the bulb center and perpendicular to said edge plane.

6. A reflector lamp comprising a bulb formed as an ellipsoid of revolution with a neck portion extending therefrom normal to the bulb axis of revolution, 9. mount disposed in said neck portion and comprising a helical filament and its lead-in conductors, the axis of said filament being straight for its entire length, said filament being located at one of the foci of the bulb, another filament supported between said focus and the center of the bulb, and a reflecting coating on more than one half of said bulb and terminating in anedge defining a plane, the axis of said helical filament intersecting a line through the bulb center and perpendicular to said edge plane.

'7. A reflector lamp comprising a bulb formed as an ellipsoid of revolution, a neck extending therefrom and coaxial with the axis of revolution thereof, a mount disposed in said neck portion and comprising a helical filament and its lead-in conductors, said filament being located at the focus of said bulb remote from said neck, the axis of said filament being straight for its entire length, and a reflecting coating on more than half of said bulb and terminating in an edge defining a plane, said filament having its axis intersecting a line through the bulb center and perpendicular to said edge plane.

8. A reflector lamp comprising a bulb generally spherical with a neck portion extending therefrom, a. mount disposed in said neck portion and comprising a flare, four supports extending from said flare, and three filaments connected to said supports, a reflecting coating on at least one half of said spherical portion, one of said filaments being mounted between the free ends of two of said supports and disposed approximateiy one half the bulb radius from the center toward said coating, another being mounted between one of said supports and another support and disposed between said first-mentioned filament and said bulb center, and the third being mounted between said common filament support and an additional support, in order to allow for energizing any two of said filaments in series, with the light from the first-mentioned filament reflected from said coating in approximately parallel rays.

9. A reflector lamp comprising a bulb formed as an ellipsoid of revolution with a neck portion extending therefrom normal to the bulb axis of SIAGLBS therefrom and coaxial with the axis of revolution thereof, a mount disposedin said neck pertion and comprising a filament located at the focus of said bulb remote from said neck and a reflecting coating on more than one-half of said ellipsoidal portion.

11. A reflector lamp comprising a bulb with a neck portion extending therefrom, a mount in said neck portion and comprising four supports and three filaments connected to said supports,

a. reflecting coating on part of said bulb, said filaments being arranged as a series between said reflecting coating and the bulb center, one of said filaments being mounted between the free ends of two of said supports and disposed at approximately the focal point of the reflecting coating, another being mounted between one of said supports and another support and disposed between said first-mentioned filament and said bulb center, and the third being mounted between said common filament support and the fourth support, in order to allow for energizing any two of said filamentsin series.

12. A reflector lamp comprising a bulb with a neck portion extending therefrom, a mount dis- I pendicuiar to said edge plane. 10

posed in said neck portion and comprising a helical filament and its lead-in conductors, the axis of said filament being straight for its entire length, and a reflecting coating on more than hair of said bulb and terminating in an edge defining a plane, said filament being oflset frpm the center of said bulb and with its axis intersecting a line through the bulb center and per- JOHN rr. KURLANDER.'

I nnrnnnncns orrim The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 625,219 Truitt May 16, 1899 1,051,542 Bissell Jan, 28,1913 1,150,738 Birch Aug. 17, 1915 1,213,933 Morey Jan. 30, 1917 1,240,583 Lakin Sept. 18, 1917 1,981,329 Rivier Nov. 20, 1934 1,998,187 Conti Apr. 16, 1935 FOREIGN PATENTS Number Country Date 4,847 Great Britain Mar. 11, 1892 300,937 Germany Aug. 18, 1915 303,844 Germany June 1919 496,683 France Mar. 7, 1919 595,666 France June 19, 1924 643,887 France Sept, 25, 1928 766,557 France .Apr. 16, 1934 

